{"id":"CVE-2026-42897","aliases":["EUVD-2026-30343","GHSA-3c39-338m-m4vp"],"status":"published","title":"Microsoft Exchange Server Spoofing Vulnerability","description":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.70662,"percentile":0.99399,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":true,"fix_available":false},"cwes":["CWE-79"],"published":"2026-05-14T17:00:36Z","modified":"2026-10-26T14:10:00Z","kev":{"date_added":"2026-05-15","due_date":"2026-05-29","required_action":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2026-05-15"},{"source":"kev","since":"2026-05-15"}],"exploits":[{"source":"pocgithub","id":"atiilla/CVE-2026-42897","title":"atiilla/CVE-2026-42897","date":"2026-05-15","url":"https://github.com/atiilla/CVE-2026-42897"}],"products":[{"vendor":"microsoft","product":"exchange_server"},{"vendor":"microsoft","product":"exchange_server_subscription_edition"},{"vendor":"microsoft","product":"microsoft"},{"vendor":"microsoft","product":"microsoft exchange server 2016 cumulative update 23"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 14"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 15"},{"vendor":"microsoft","product":"microsoft exchange server subscription edition rtm"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42897","tags":["vendor-advisory","patch","Mitigation","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-42897","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42897"},{"url":"https://github.com/advisories/GHSA-3c39-338m-m4vp"}],"sources":{"cve":[{"id":"CVE-2026-42897","title":"Microsoft Exchange Server Spoofing Vulnerability","description":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-05-14T17:00:36.515Z","modified":"2026-08-10T15:14:02.885Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T13:40:23.731501Z"}],"euvd":[{"id":"EUVD-2026-30343","description":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-05-14T17:00:36Z","modified":"2026-08-10T15:14:02Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C","level":"high"}],"exploited_since":"2026-05-15","updated_at":"2026-11-02T18:02:01.941928Z"}],"ghsa":[{"id":"GHSA-3c39-338m-m4vp","title":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft...","description":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-05-14T18:32:57Z","modified":"2026-05-15T18:30:32Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:08:10.185094Z"}],"kev":[{"id":"CVE-2026-42897","title":"Microsoft Exchange Server Cross-Site Scripting Vulnerability","description":"Microsoft Exchange Server contains a cross-site scripting vulnerability during web page generation in Outlook Web Access and when certain interaction conditions are met, arbitrary JavaScript can be executed in the browser context.","cwes":["CWE-79"],"kev":{"date_added":"2026-05-15","due_date":"2026-05-29","required_action":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:15.999436Z"}],"nvd":[{"id":"CVE-2026-42897","description":"Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-05-14T18:16:49.36Z","modified":"2026-10-26T14:10:00.13Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:19.020465Z"}]}}